The invention relates generally to techniques for electromagnetic resistance determination within volumetric spaces. In particular, the invention relates to determining surface resistivity of various materials within a chamber, based on comparison with established references.
Statements herein are not to be interpreted as admissions about what is prior art or what is not prior art. Applicants incorporate herein by reference the entire teachings of U.S. Pat. No. 4,733,165. Cavity perturbation measurement on materials with a single-mode cavity is a well-known microwave technique. However, for a large test sample or structure compared against the test frequency wavelength, then the single-mode cavity approach cannot be successfully applied because of difficulties to excite and maintain a single mode in a cavity that is large in terms of wavelength. Further information can be obtained from NSWCDD/TR-081127, “Reverberant Microwave Propagation” by Robert E. Richardson.